Recently, many sterilizing methods and sterilizing apparatuses have been introduced that sterilize water in a preliminary stage by introducing gases with strong sterilizing properties, such as hydroxyl radicals (OH), active oxygen (O—, O2, O3), and hydrogen peroxide (H2O2) into water, and supplying the sterilized water to a certain compartment or item to sterilize the latter. Such sterilized water is useful in sterilizing applications for the food processing and distribution industry, animal husbandry, hospitals, and other fields that require sterilization.
Also, there are many efforts currently underway to combine household appliances (such as air conditioners with heater/cooler functions, air cleaners, and humidifiers) with in-water discharging technology to maintain indoor air in a clean state by removing bacteria and viruses from water.
A method based on the bubble mechanism theory discharges bubbles of active oxygen and ozone, using a discharge cell with electrodes immersed in water to generate short bursts of powerful electric fields at the discharge cell and generate discharged heat from the electrodes. Thus, the water is vaporized by the discharged heat, forming bubbles. These bubbles can easily be discharged with a weak electric field, to induce sudden dielectric breakdown of water. In this process, radicals, that is, hydroxyl radicals (OH), oxygen-free radicals (O—O), and hydrogen peroxide (H2O2) are generated.
The radicals generated in the above in-water discharging process oxidize metals contained in the water and also sterilize bacteria and viruses in the water while removing viral and bacterial spores at the same time.
When a discharge cell continues to be discharged after various harmful impurities in the water have been removed, the radicals accumulate in the water. Thus, the water containing the gases is given innate sterilizing properties, so that the sterilizing water can be used for various sterilizing and cleaning tasks.
However, in-water discharging apparatuses according to the related art have the following limitations.
In order to facilitate in-water discharge in the related art, miniature bubbles are introduced from the outside. That is, miniature bubbles are introduced from the outside to form an oxygenated atmosphere around the discharge electrodes, and then discharging is performed by applying a high voltage.
In another type of in-water discharging according to the related art, a needle electrode is designated as a high voltage electrode and is enclosed by a dielectric vessel such as a glass tube within a water tank, and the water inside the water tank is designated as a ground electrode. Through primary electrolysis, oxygen bubbles are generated within the dielectric vessel. Then, the bubbles fill the inside of the tank to produce an oxygenated atmosphere, and in-water discharge is performed. In this configuration, when a single needle electrode is used as a high voltage electrode for electrolysis, without oxygen being separately introduced from the outside, there is the limitation in that a large quantity of miniature bubbles cannot be generated.
Another related art in-water discharging method involves the use of a mechanical high-speed rotational spark cap for generating in-water discharge, instead of employing oxygen injection or electrolysis to generate oxygen bubbles. This method is used largely for industrial application, and has the drawback of being difficult to miniaturize for home appliances.
In related art in-water discharging methods employing electrolysis, a high voltage electrode is separated from a corresponding electrode (ground electrode), and a field strength magnifying device is provided separately to increase field strength for facilitating the generation of bubbles at the high voltage electrode. Here, electrolysis causes oxidation of the high voltage electrode, compromising the reliability of the electrode.
While in the past, humidifiers mostly generated moisture by employing ultrasound or steam, only recently have humidifiers that employ natural evaporation humidifying through the use of non-woven fabric or paper materials been commercialized.
However, related art humidifiers using the above methods have the following limitations.
First, in the case of ultrasonic humidifying, chlorosis occurs around the oscillator after prolonged use.
Also, when water is retained for a long period in a water tank without being used, impurities enter the water tank from the atmosphere and contaminate the water stored in the tank, thus presenting sanitary problems.
In the humidifying method using steam, not only are there the problems of chlorosis and sanitary problems, but considerable power is consumed in generating steam.
Moreover, humidifiers that employ ultrasonic humidification, steam humidification, and natural evaporation humidification are locally effective only. That is, humidification of regions remote from the position of the humidifier is ineffective, thus presenting the limitation in that indoor humidity cannot be uniformly maintained.
Particularly with ultrasonic humidification, when the size of atomized water particles is large, the floor around the humidifier can become wet, causing a user to slip, and mold can form on floor or wall surfaces.
Furthermore, because there are no sterilizing devices to sterilize water stored in water tanks of related art humidifiers, a separate sterilizing solution must be added when filling a water tank with water.
Also, in the case of related art humidifiers that employ natural evaporation using non-woven fabric or paper materials, the lifespan of the humidifying device is short.